Methods for synthesizing macroscale 3D heteroatom-doped carbon nanotube materials (such as boron doped carbon nanotube materials) and compositions thereof. Macroscopic quantities of three-dimensionally networked heteroatom-doped carbon nanotube materials are directly grown using an aerosol-assisted chemical vapor deposition method. The porous heteroatom-doped carbon nanotube material is created by doping of heteroatoms (such as boron) in the nanotube lattice during growth, which influences the creation of elbow joints and branching of nanotubes leading to the three dimensional super-structure. The super-hydrophobic heteroatom-doped carbon nanotube sponge is strongly oleophilic and can soak up large quantities of organic solvents and oil. The trapped oil can be burnt off and the heteroatom-doped carbon nanotube material can be used repeatedly as an oil removal scaffold. Optionally, the heteroatom-doped carbon nanotubes in the heteroatom-doped carbon nanotube materials can be welded to form one or more macroscale 3D carbon nanotubes.

Provided is a fibrous carbon nanostructure dispersion liquid having excellent fibrous carbon nanostructure dispersibility. The fibrous carbon nanostructure dispersion liquid contains a solvent and one or more fibrous carbon nanostructures that exhibit a convex upward shape in a t-plot obtained from an adsorption isotherm.

The present invention provides a conductive material for a secondary battery, and a secondary battery containing the same, the conductive material comprising carbon nanotubes, having a secondary structure in which carbon nanotube units having a diameter of 20-150 nm are entangled, having a ratio of true density to bulk density (TD/BD) of 30-120, having a metal content of 50 ppm or less, and having both excellent dispersibility and high purity, thereby being capable of improving, by increasing the conductivity within an electrode, battery performance, particularly, battery performance at room temperature and low temperature when applied to a battery.

Provided herein are methods and devices for production of carbon nanotubes (CNTs) which have high structural uniformity and low levels of impurities. The device includes, for example, a module for depositing catalyst on a substrate, a module for forming CNTs, a module for separating CNTs from the substrate, a module for collecting the CNTs and a module for continuously and sequentially advancing the substrate through the above modules. The method includes, for example, the steps of depositing catalyst on a moving substrate, forming carbon nanotubes on the substrate, separating carbon nanotubes from the substrate and collecting the carbon nanotubes from the surface, where the substrate moves sequentially through the depositing, forming, separating and collecting steps.

Methods for synthesizing macroscale 3D heteroatom-doped carbon nanotube materials (such as boron doped carbon nanotube materials) and compositions thereof. Macroscopic quantities of three-dimensionally networked heteroatom-doped carbon nanotube materials are directly grown using an aerosol-assisted chemical vapor deposition method. The porous heteroatom-doped carbon nanotube material is created by doping of heteroatoms (such as boron) in the nanotube lattice during growth, which influences the creation of elbow joints and branching of nanotubes leading to the three dimensional super-structure. The super-hydrophobic heteroatom-doped carbon nanotube sponge is strongly oleophilic and can soak up large quantities of organic solvents and oil. The trapped oil can be burnt off and the heteroatom-doped carbon nanotube material can be used repeatedly as an oil removal scaffold. Optionally, the heteroatom-doped carbon nanotubes in the heteroatom-doped carbon nanotube materials can be welded to form one or more macroscale 3D carbon nanotubes.

Provided herein are methods and devices for production of carbon nanotubes (CNTs) which have high structural uniformity and low levels of impurities. The device includes, for example, a module for depositing catalyst on a substrate, a module for forming CNTs, a module for separating CNTs from the substrate, a module for collecting the CNTs and a module for continuously and sequentially advancing the substrate through the above modules. The method includes, for example, the steps of depositing catalyst on a moving substrate, forming carbon nanotubes on the substrate, separating carbon nanotubes from the substrate and collecting the carbon nanotubes from the surface, where the substrate moves sequentially through the depositing, forming, separating and collecting steps.

The present invention relates to carbon nanotubes that are excellent in dispersibility and a process for producing the carbon nanotubes. The carbon nanotubes according to the present invention each comprise a wall that comprises a parallel portion and a narrowed portion having a tube outer diameter that is not more than 90% of a tube outer diameter of the parallel portion. Thus, the carbon nanotubes are readily dispersible owing to a high abundance ratio of easily-breaking portions.

A fibrous carbon nanostructure dispersion liquid contains a solvent and fibrous carbon nanostructures having at least one absorption peak in a wavenumber region of 500 cm.sup.1 to 600 cm.sup.1 in a light absorption spectrum.

The embodiments of the present disclosure relate to a method and apparatus for producing a carbon nanomaterial product (CNM) product that may comprise carbon nanotubes and various other allotropes of nanocarbon. The method and apparatus employ a consumable carbon dioxide (CO.sub.2) and a renewable carbonate electrolyte as reactants in an electrolysis reaction in order to make CNTs. In some embodiments of the present disclosure, operational conditions of the electrolysis reaction may be varied in order to produce the CNM product with a greater incidence of a desired allotrope of nanocarbon or a desired combination of two or more allotropes.

Provided is a surface-treated carbon nanotube having few surface fractures, not reducing the molecular weight of the resin to be mixed and having excellent extrudability. In the surface-treated carbon nanotube, the thermal reduction amount at 600 C. in a nitrogen atmosphere is 0.2 to 40%, the surface oxygen concentration measured by X-ray photoelectron spectroscopy (XPS) is 1.5 to 40 atm % and the surface sulfur concentration is less than 0.1 atm %.